1. Field of Invention
This invention is directed generally to bearing assemblies, and more particularly to a sealed bearing end cap adapted for attachment to a bearing assembly mounted to a rotating shaft.
2. Background of the Invention
For years, bearing assemblies have been used on rotating shafts. For example, in automated conveyor lines, bearing assemblies are mounted to rotating shafts. In many applications, the bearing assemblies are subjected to harsh operating conditions involving liquid, gaseous, and solid contaminants. The field of beverage bottling presents one particularly harsh environment. Bearings are subjected to spilled juices such as orange and grape juice, and acidic lemonade. Sports drinks, beer, ginger ale, and cola also represent harmful contaminants that may come in contact with the bearing and reduce bearing life. Other packaging and handling environments also subject bearing assemblies to potentially caustic materials. In these applications, it is very important for the lines to continue running, without unscheduled downtime. A bearing failure can result in shutting an entire line down while repairs or replacement bearings are provided. Such costly downtime is to be avoided at all costs.
Consequently, efforts have been made to provide corrosion resistant bearings and bearing assemblies that include various, and oftentimes, intricate sealing arrangements. One such line of bearings is the SEALMASTER(copyright) Gold Line Corrosion Resistant Bearings that are specially designed and manufactured for abrasive and wet environments. In addition, bearing end caps have been provided at the end of a rotating shaft to provide an additional line of defense against harmful contaminants and potentially corrosive materials. One such bearing end cap has been provided in the form of a stainless steel end cap that is typically bolted to the bearing housing. As an alternative to a bolted mounting, the end cap can be provided with exterior retention snaps that snap fit into a corresponding groove in the housing to mount the end cap to the bearing housing. The end cap may be either closed, where the end of the rotating shaft is positioned inside the end cap, or it may be open, where the rotating shaft is allowed to pass the through the end cap. The use of bearing end caps in such situations has provided an added measure of protection to keep contaminants out of the bearing. To provide further protection for the bearing, a seal may be placed between the end cap and the bearing housing. Some end caps are provided with an O-Ring type elastomeric seal that is placed within a mounting surface of the end cap. While providing some additional protection, this type of seal suffers from several drawbacks. First, the O-Ring seal does not provide the maximum sealing between the end cap and the bearing housing. In addition, bearing end caps are often removed from bearing housings during maintenance and cleaning. The O-Ring is separate and distinct from the end cap and can become separated and lost while the end cap is removed. When an O-Ring becomes lost with no replacement readily available, the end cap may be reattached to the bearing housing without the use of any seal. This is undesirable because contaminants and other materials can more easily infiltrate the bearing.
Accordingly, there is a need to provide a bearing end cap having improved sealing capabilities. In addition, there is a need to provide a sealed bearing end cap where the seal cannot be separated from the end cap and subsequently misplaced or lost. In addition, there is a need to provide a low-cost method of producing a sealed bearing end cap.
The present invention is specifically directed to a bearing end cap adapted for mounting to a bearing housing. The bearing end cap includes a circular mounting surface positioned on a front surface of the end cap. The circular mounting surface is adapted to be mounted into a corresponding circular groove of the bearing housing. The end cap preferably includes a retention ring having a plurality of spaced apart retention snaps that interact with a circular groove of the bearing housing to secure the end cap to the bearing housing. In the disclosed embodiments, the end cap is provided with an integrated seal positioned in an annular seal groove on the mounting surface of the end cap. The integrated seal is preferably overmolded onto the annular seal groove of the end cap in a secondary molding operation. The integrated seal provides a seal between the mounting surface of the end cap and the bearing housing. In addition, the integrated seal may also extend to cover the retention snaps to provide a seal between the retention snaps and the circular groove of the bearing housing. Further, the end cap may also be provided with a secondary integrated seal positioned radially outwardly from the retention ring of the end cap to provide additional sealing between the end cap and the bearing housing. The disclosed embodiments provide for improved sealing between the end cap and the bearing housing. In addition, the overmolded integrated seal reduces the chance that the seal will become separated from the end cap and misplaced or lost, and ensures that the seal will be in proper position when the bearing end cap is attached to the bearing housing. Moreover, the end cap with an integrated seal can be cost-effectively manufactured using conventional injection molding and overmolding techniques.